Electric signaling



FIG.

May 2, 1944.

A. w. HORTON, JR 2,348,131

ELECTRIC SIGNALING v v 7 Filed June 27, 1942 4 Sheets-Sheet 1 A7TOR May 2, 1944.

l l I A. W. HORTON, JR ELECTRIC S IGNALING Filed June 27, 1942 4 Sheets-Sheet 2 macaw Quantum It I i A T TOR/VEV May 2, 1944. w, HQRTQN, JR 2,348,131

ELECTRIC. SIGNALING Filed June 27, 1942 '4 Sheets-Sheet 3 FIGS INVENTOR A. WHOMUMJR.

wv w A rTORA/ y 1944. A. w. HORTON, JR 2,348,131

ELECTRIC SIGNALING Filed June 2'7, 1942 4 Sheets-Sheet 4 FIG. 7

W WW A 7' ORNFV Patented May 2, 1944 UNITED STAT ES PATENT OFFICE.

I j 2,348,131 I j Arthur W. N. 1., as-

" signor to Bell Telephone Laboratories, Incorpof rated, New York, N. Y., a corporation of New York Application June 27, 1942, Serial No. 448,732 6 Claims. (cl. 179-27) This invention relates to electric signaling, particularly when employed in connection with the operation of automatic telephone systems.

The objects of the invention are to obtain greater economy and simplicity than heretofore realized in the mechanisms'used for identifying the lines, trunks, or other electric circuits of a large group; to enable the use of photoelectric devices for efiecting the identification and at the same time to reduce to a minimum the amount of associated amplifying equipment necessary; and to efiect other improvements in systems of this general character.

The foregoing objects of the invention are realized in a system in which the lines of a group are identified and their designations determined by means in a field .or array of signal lamps and light sensitive elements which serve to energize sets of light sensitive elements in code combinations representing the line numbers or designations and in which the light sensitiveelements cause the operation of indicating or registering -means. More specifically, the signal lamps, which represent individually the specific lines of the group, such asthe ten thousand lines in a telephone office, are arranged on a decimal basis in a field of coordinate rows, and a plurality of setseof light sensitive elements, preferably in the form of continuous strips, are provided for each row of lamps and are secured to the structure in proximity to the lamps so that any lamp in the row is capable of projecting its light onto all strips of the several setspertaining-to such row. The several sets of light sensitive strips opposite each row of lamps represent respectively the digital places in the designations of the telephone lines.- That is to say; if there are ten thousand lines, each having a four-place designation, four sets of light sensitive strips are provided for each row of lamps. Each set of light sensitive strips contains fewer strips than there are character values for the corresponding digit, and the digit values represented by each lamp are translamd to the light sensitive sets by exposing the-strips of each set to the lamp income binationsrepresenting a selected code. The desired choice of strips to produce the code for each line isobtained by introducing a screen between the lamps in each row and the associated associated number, whereasrall other strips are ,maskedso as not tobeaifected by the lamp.

may be obtained by the use of simple photoelectric means which is capable of translating The light sensitive strip of the correspond n sets in all rows are mul ip es! an are conn cted through suitableamplifying means to code registers, of which there is one for each digital place in the designation. If, as assumed, the line designations have four digital places and'a fourunit code is used, there would be four registers each comprising four relays.

' An advantage of this system is that the identification of any one of a large number of lines the decimal designations of the lines into a simple code which can readily serve its intended purpose in an automatic telephone system. By

reducing the decimal designations of the lines to a code comprising a relatively small number of elements, the amount of amplifying equipment usually necessary where photoelectric devices are employed is correspondingly reduced v to a minimum. v 1

" -A feature of the invention is an identifying system in which some of the strip sets, such as the thousands and hundreds sets, are arranged. along the horizontal rows of lamps, and others,

vided with an opaque covering over all areas except those determining the desired code foreach of the four sets of strips, and the overlapping strips are insulated from each other by a thin f lm of transparent insulating material to prevent the formation of false current paths. More specifically, the intermediate transparent plate is darkened uniformly at all lamp positions in those areas where the horizontal and vertical s rips oss each other. In those ar as wh e the light from any particular lamp is capable ,of

fgive the required odes f that lamp position- Theseand other J-featuresfof. the. inventio will be described more fully, inlthe following setailed specification.

. In the drawings ac ompany ng the specifi a- .tiopn:

Figs. '1 and 2 comprise a conventional diagram illustrating an automatic telephone systemarranged for .call n l ns iden ifieati ngz Fig. -3 is an enlarged crossesectional detail of the identification panel illustrated in Fi-g. 1

, number of the associated line.

I have been omitted in the drawings.

' the No. 0, No. 8 and No. 9 tens groups.

Fig. 4 is an enlarged detail of one of the light sensitive strips;

Fig. 5 shows an alternative form of the identification lamp panel;

Fig. 6 is an enlarged cross-sectional detail of the panel shown in Fig. 5; and

Fig. 7 is a diagram. of the lamp panel illus trating the numbering arrangement.

The present invention is particularly useful in systems that require the preparation of tickets for the purpose of assessing calling telephone" subscribers for the'conversations held with other subscribers. Since these tickets are prepared automatically, it is necessary to'determinethe number of the calling line in order'that the charge may be assessed against the proper party.

However, the invention may be used in any type of system whereit is desirable to determine auto-' matically the identity of a line, trunk, cir cuit=or other device. For example, it is often desirable to'display the number of a calling party before an operator to whom the line has been extended, thereby eliminating the necessity for the operator to make an oral request or to perform a number-checking operation.

Referring to Figs..1 and 2, the automatic telephone system illustratedherein comprises a large group of lines, usually ten thousand, which appear in the central office in hon-numerical switches, such as finder switches. The line I00 illustrated in the drawings appears in the bank of line finder-switch F which in turn is associated with the first selector switch S. Theselector S may; have direct access to outgoing trunks or, as shown in the drawings, it may have:

access through a succeeding selector S-I to these outgoing trunks, such as the trunk IOI, outgoing to distant offices.

The designation or identity or each line that establishes a toll call over one of the outgoing.

trunks IOI is obtained by the field or panel of signal lamps shown in Fig. 1. This lamp panel includes a lamp for each of the ten thousand lines in the ofiice and each lamp represents the arranged in decimal order in coordinate horizontal and vertical rows, there being one hundred horizontal rows and one hundred vertical rows, each row inrboth directions containing one hundred lamps. r

Referring for the moment to Fig. 7, which illustrates the lamp formation more clearly, the hundred horizontal rows are divided into. ten

, equal groups, one for each thousand lines. For

example, the horizontal group of lamps 100 represents the No. 0 thousands group of lines, the horizontal group of lamps 10I represents the No. 1 thousands group of lines, the horizontal group 102 represents the No. 9 thousands group of lines, and similarly for the remaining groups which Each of these thousands groups contains ten horizontal I rows of one hundred lamps representing the F s. 1 and '3 comprises'a back panel- I02 on which the ten thousand lamps are mounted in" The lamps arei H4 and shields.

one hundred horizontal rows and one hundred vertical rows. These lamps are located in individual chambers formed by a series of horizontal shields or separators I03, I04, I05, I06, I01 and a series of intersecting vertical separators I00, I09, IIO, III, II2, etc. The lamp chambers formed, by these intersecting shields may be covered on the front by a single plate, or, as illustrated in Fig. 3, by individual plates II3 closing the area between the horizontal shields H5 and the corresponding vertical The plates or screens I I3 at the various lamp positions are'provided with slots or Windowsllfi', II1 ,'-II8, II9, I20, I2I, located in accordance with the desired code, to permit the emission of light from the associated lamp, such as lamp I22. 'Arr'anged across the front of the plates I I3 in horizontal rows are four sets of photosensitive strips I23, I24, I25 and I26. These four sets represent the four digital places of the designations, and each set contains four strips which, when taken in different code combinations, furnish the ten different values of the digit. These photosensitive strips are seen in cross-section in Fig. 3, some of them occurring adjacent the light emitting windows and others occurring adjacent the solid portions of plate II3. Each one of these strips (see Fig. 4) comprises a backing I90 of some material, such as cloth, having conducting ribbons I9I and I92 afiixedto the edges thereof and a layer of photosensitive substance such as selenium covering the surface between the conducting ribbons. Light shining on the photosensitive substance causes a current or voltage change in the electrical circuit I93 connected to the conducting ribbons which may be utilized in the manner disclosed I more fully hereinafter.

Referring particularly to Fig. 1, the first one hundred horizontal rows of lamp positions I21, I28, etc., constitute the ten hundreds in the No. O'thousand. Similarly, the succeeding horizontal rows of lamp'positions, including the last row I29, constitute the hundreds groups of the remaining thousands groups. In the horizontal direction of the panel the first ten vertical rows of lamppositions I30, I3I, I32, I33, etc., constitute'the ten different units values of the No. 0 tensdigit. Similarly, the succeeding vertical rows, including the last two rows I34 and I35, constitute the units values of the remaining tens digits. This, of course, is the same decimal arrangement' of the lamps as the one illustrated in the diagram of Fig. '7. The four sets of photosensitive strips I36, I31, I38, I39, serving the horizontal row I21 are arranged as illustrated across thefront of'the plates II3.

These strips, which .are illustrated in Fig.11 by single -lines, are connected by conductors I40, I4I, I42,

I43 to four groups of individual amplifiers I44,

I45, I46, I41. The four sets of photoelectric strips I48, I49, I50, I 5| serving the secondhorizontal row of lamps I28'are similarlyarranged across I :the front of the areaand are multipled respectively to the conductor groups I40, I, I42, I43.

In like manner each of the remaining horizontal groups of lines in the area is, provided. with similar sets of, photoelectric strips, andsthese strips are all multipled to the conductors I40,

"through a connecting medium if desired; to the MI, 142 and l43wlea'ding to the amplifiers I44,

I45, I40 and M1. The output circuits Jlead,

mechanism I 56 is in turn iconnectable to the Register relays 2 and 4. l.

'1 and 2. 3.

l and 3. 2 and 3. 1, 2 and 3. 4

' ram 4.

To cause the operation of the register relays I52, I53, I55 and I55 in accordance with the code above given, the screens II3 before the various lamp positions are provided with windows correspondingly located with respect to the photoelectric strips of the four difierent sets. For example, the lamp located in the position at the intersection of horizontal row I21 and vertical row I30, namely, in the upper left-hand corner of Fig. 1, represents line number 0000. In other words, this line is in the No. thousands group, in the No. 0 hundred of the thousand, in the No. 0 tens group of the hundred, and in the No. 0 units position in the group of ten. Accordingly, to register the designation of this line it is necessary to energize relays 2 and 4 in each of the thousands, hundreds, tens and units registers I52, I53, I54 and I55. Therefore, the plate H3 in front of the lamp is provided with windows opposite the second and fourth strips I59 and I60 of the thousands set I36 and also opposite the second and fourth strips of each of the hundreds, tens and units sets I31, I38 and I39. Thus, when the lamp is illuminated, light therefrom Shines through the windows I EI, I62, I63, I54, I65, I66, I51 and I68 to energiz the associated strips, whereas the other two strips in each of the four sets remain unaffected. When line number 0001 is involved,the associated lamp located at the intersection of horizontal row I21 and vertical row I3I is illuminated, and light shines on the second and fourth strips in eachof the thousands, hundreds and tens sets I36, I31 and I38 and on the first strip I59 inthe units set I39. Consequently the No. 2 and No. 4 relays of registers I52, I53 and I54 and the No. 1 relay of register I55 are operated. And it will be found that the location of the light windows before all other lamps in the area corresponds with the desired code.

A description will now be given of the operation involved in the process of identifying a subscribers line. Assume for this purpose that the subscriber of line I00 desires to make a toll call for which a ticket should be prepared to record the nature of the call and th charge therefor. When the subscriber initiates the call, the line finder F finds his line and extends it to the usual pulsing mechanism associated with the first selector switch S. The switch S and the switch S-I respond to successive series of impulses transmitted by the subscribers dial [it to extend his line to an idle trunk IOI outgoing in the desired direction. At any suitable tim 'dur ing the extension of the connectionof thesubscribers line to the trunk IOI an idle registering mechanism I56 is associated with the trunk IIII by means of a connecting device I53. The subscriber continues to dial the remaining digits of the wanted designation, and these digits may, if desired, be registered in the mechanism I56 where they are later used to control the operation of the switches in the offices beyond and also to furnish the required information for printing the designation of the called subscribers line.

As soon as the mechanism I56 is ready to receive the identification of the calling line I66, it establishes connection with the identifying lamp equipment through suitable connectors provided for that purpose. Also a circuit is closed from the source of energy I1I over conductors I12, connector I58, conductor I13, thence over the sleeve connection through switches SI, S and F to the sleeve conductor I14 of the subscribers line I00. The circuit is completed from conductor I14 through the condenser I15, conductor I16 through the filament of lamp I11 to ground. It will be seen from the position occupied by the lamp I11 in the area that the designation of the-line I00 is 0102. Accordingly the codewindows before this lamp .permit light to shine on strips I18 and I19 in set I48, on strip I80 in set I49, on strips I 8I and I82 in set I50, and strip I83 of set I5I. The current flowing in the circuits connected to the energized strips is amplified by amplifiers I84, I85, I86, I81, I58 and I89 and is then applied to the registers, causing the operation of the No. 2 and No. 4 relays of register I52, the No. 1 relay of register I53, the No. 2 and No. 4 relays of register I54 and the No. 2 relay of register I 55. Any suitable means may be provided in the mechanism I56 for transferring the information on the registers to the controlling circuits I51 where it serves to operate a ticket printer to print the number of a subs-cribers line together with other information about the call. After all the necessary operations have been performed, the registering mechanism I56 is disconnected from the identifying lamp equipment and from the controlling circuits I51.

The mechanism I56 corresponds in itspurposes and operation and, if desirable, may also correspond in large measure with the structure of the register-sender and identifying mechanisms fully disclosed and described in Gooderham 2,350,- 829 of November 3, 1942., and in the applicaticn of Gooderham, Serial No. 448,782 filed June 2'7,

1942. The thousands, hundreds, tens, and units,

digits of the calling number are registered on registers I52, I53, I54 and I55 as above described, and these registers then control the ticket print ing apparatus associated with control circuits I51.

Also the control mechanism I51 individual to trunk IBI may be the same in structure and in operation as the corresponding mechanism fully shown and described in the Gooderham patent and application; Reference is, therefore, made to this patent and application for a full understanding of the manner in which the mechanism I56 is seized in response to th dialing by the calling subscriber and connected to the. ticketing trunk IBI through the connector I58, of the manner in which the digits of the called line are registered in mechanism I56, of the manner in which the tone current is sent from source I1I over the sleeve of the connection to cause the identifying circuits to identify the particular line calling andtoregister the digits of the numher of this line in the mechanism 156, of .the manner in which the printer and trunkqcontrolling mechanism 15'! operates, and of the manner in which these identification systems operate in any other respect that may be helpful to an understanding of the application ofrthe present invention.

In the alternative identifying lamp structure illustrated'in the enlarged details of Figs. and 6, the front of the lamp chambers of the entire area is covered with a, plate 500 of transparent material such as glass. The four sets of photosensitive strips are then mounted on the glass plate 500 ina manner somewhat different from that illustrated inFigs. 1 and 3. Instead of arranging all foursets in parallel along the horizontal row of lamps, two of these sets are arranged horizontally, and the othertwo are arranged vertically. That is to say, the thousands set of strips 501 and the hundreds set 502 are disposed along the horizontal row, 503 of one hundred lamp positions; and the tens set 504 and the units set 505 are disposed along the vertical row 50B of one hundred lamp positions. As best seen in Fig. 6 the horizontal sets of strips are mounted directly on the surface of the glass plate 500 and are separated from .the vertical sets of strips by means of a thin plate of transparent insulating material 501, which may also be of glass. The light from the lamp 508 at each position is directed to the four sets of strips in accordance with the proper code by means of a mask applied to the surface of the plate 500. This mask may comprise a coat of black paint or any other suitable substance applied to all areas of the plate 500 except those through which it is desired to have the light shine upon the photosensitive strips. This is illustrated in the figures in which it will be noted that the position occupied by lamp 508 at the intersection of the horizontal row 503'and the vertical row 506 corresponds to line 0000. The code of this number is obtained by applying the opaque coating to the entire surface of the plate 500 in front of the lamp except the areas 510 and 511 of the thousands set, areas 512 and 513 of the hundreds set, areas 514 and 515 of the tens set and areas 516 and 511 of the units set. When, therefore, the signal lamp 508 is illuminated, light shines through the transparent windows 510 and 511 to energize the second and fourth thousands strips 518 and 510, through windows 512 and 513 to energize the second and fourth hundreds strips 520 and 521, and similarly through windows 514 and 515 and 516 and 51'! to energize the corresponding strips in the tens and units sets 504 and 505.

What is claimed is: r

1. In a telephone system in which designations are assigned to the lines of a group on a decimal basis, each designation having a plurality of digital places, the combination of a plurality of signal lamps individual respectively to the lines of said group, said lamps being arranged in decimal order in a, field of coordinate rows, a plurality of sets of light-sensitive strips fixed before each row of lamps in one coordinate direction, said sets corresponding respectively to the digital places of the designations, the number of strips in each set being less than the number of possible digit values in the corresponding digital place, a screen interposed between said lamps and said strips and designed to permit the light from each lampto impinge upon a combination "of the strips in each of the associated sets representing in code the decimal designation of said lamp and its individual line, means for lighting the lamp of any desired one of said lines to energize the light sensitive strips before such lamps, and means responsive to the combination of energized strips for indicating in code the designation of said desired line.

2. In a signaling system having a group of lines provided with individual designations, each .of which has a plurality of digital characters, the

combination of a plurality of signal lamps individual respectively to said lines, said lamps being arrayed in a field of coordinate horizontal and vertical rows bearing a definite relation to the values of the designation characters of said lines, a plurality of sets of light sensitive elements afiixed before each row of lamps in one of said coordinate directions, each of said elements having an appearance before every lamp in the associated row, said sets of elements corresponding respectively to the digital characters of said designations, a screen interposed between said lamps and said light sensitive elements and designed to permit the light from each lamp to impinge upon a combination of said elements representing the designation characters of said lamp and its individual line, means for lighting the lamp of any desired one of said lines to energize said light sensitive elements, and means responsive to the energized elements for indicating the designation of said desired line.

3; In a signaling system having a group of lines provided with individual designations, each of which has a plurality of digital characters, the combination of a plurality of signal lamps individual respectively to said lines, said lamps being arrayed in a field in a plurality of rows, the order of the individual lamps in said rows bearing a definite relation to the values of the designation characters of said lines, a plurality of sets of light sensitive strips fixed before each row of lamps, each of said strips having an appearance before all lamps in the associated row, conductors for connecting the corresponding strips of all rows in multiple relation, a screen interposed between said lamps and said strips and designed to permit the light from each lamp to shine on a combination of the strips representing the designation of the associated line, means for lighting the lamp of any desired one of said lines to energize the light sensitive strips and to cause current to flow in said conductors, and means responsive to said current flow for indicating the designation of said desired line.

4. In a signaling system having a group of lines provided with individual designations, each of which has a plurality of digital places, the combination of a plurality of signal lamps individual respectively to said lines, said lamps being disposed in a field in a definite relation with respect to the designations of the associated lines, a plurality of light sensitive elements fixed before the lamps in said field, an opaque member disposed between the lamps and said light sensitive elements, said opaque member having windows therein to permit the light from said lamps to shine on said light sensitive elements in combination representing the designations of said lines, and means controlled by the energized light sensitive elements for establishing the designation of any desired one of saidlines.

5. 'In a signaling system having a group of lines provided with individual designations, each of respectively to said lines, said lamps being disposed in a field of coordinate horizontal and vertical rows, the order of the individual lamps in said field bearing .a definite relation to the values of the digital characters in said digital places, shields arranged between said horizontal and vertical rows to form light chambers, one for each lamp, each chamber serving to confine the light from the associated lamp, a plurality of sets of light sensitive elements disposed along each row of lamps in one coordinate direction, each element in each of the sets which serves a particular row having an appearance before all of the lamps in such row, the several sets assigned to each row corresponding respectively to the digital places of the designations of the lamps represented by such row, a light screen covering all of said light chambers and interposed between the lamps and said light sensitive elements, said light screen having windows at each lamp position for admitting light to the light sensitive elements of each associated set in combinations representing the values of the digital characters in the corresponding digital places, means for lighting the lamp representing any desired one of said lines to energize the associated light sensitive elements, and means controlled by said energized elements for establishing the designation of said desired line.

6. In a signaling system, a group of lines provided with individual designations, each designation having a plurality of digital characters, a plurality of signal lamps individual respectively to said lines, said lamps being arranged in a field of coordinate horizontal and vertical rows and in an order bearing a definite relation to the designation characters of said lines, a plurality of sets of light sensitive elements for each horizontal row of lamps, each of said sets representing one of the digital characters of the designations of the lines represented by the horizontal row,

a plurality of sets of light sensitive elements for each of said vertical rows of lamps, each of said latter sets representing respectively one of the digital characters of the designation of the lines represented by the vertical row, a light screen interposed between the lamps of said field and said light sensitive elements, said screen having windows at each lamp position for permitting light to shine on the light sensitive elements of each of the sets serving the corresponding horizontal row and on each of the sets serving the corresponding vertical row in combinations representing the several characters of the designation of the associated line, and means controlled by the energized light sensitive elements for establishing the designation of any desired one of said lines.

ARTHUR W. HORTON, JR. 

